Isolation of bat sarbecoviruses of SARS-CoV-2 clade, Japan

Abstract

Betacoronaviruses have caused 3 outbreaks in the past 2 decades. SARS-CoV-2, in particular, has caused a serious pandemic. As the betacoronaviruses are considered to originate from bats, surveillance of bat betacoronaviruses is crucial for understanding the mechanism of cross-species transition and potential for future outbreaks. We previously detected and characterized a SARS-CoV-2-related sarbecovirus, Rc-o319, from Rhinolophus cornutus in Japan. Here, we detected several bat sarbecoviruses of the SARS-CoV-2 clade from R. cornutus in multiple locations in Japan, and successfully isolated them using Vero/TMPRSS2 cells stably expressing R. cornutus ACE2 (Vero-RcACE2). The coding sequences of S1 region varied among isolates, whereas other genetic regions were highly conserved. Isolates were efficiently grown in Vero-RcACE2 cells, but did not replicate in Vero/TMPRSS2 cells stably expressing human ACE2, suggesting a narrow host range. Further long-term epidemiological studies of sarbecoviruses in wildlife are expected to facilitate the assessment of the risk of their spillover potential.